Such spray pumps are used to draw liquids from containers and for the spraying, or atomizing of a predosed quantity of liquid. These spray pumps having casings connectable to the container are actuated mechanically from the outside by means of levers or the like, acting upon the different pumping devices. Due to the negative pressure resulting each time, a certain amount of liquid is aspired from the container through an aspiration tube, whereby in the container atmospheric pressure is maintained. The aspired liquid is directed towards a spray nozzle via a liquid supply duct, due to further pressure on the pump piston; in front of the spray nozzle a swirl chamber, for instance, can be mounted. During each compression stroke, the container is ventilated, so that the atmospheric pressure in the container is reestablished.
Spray pumps of various kinds are known which, for instance, can be threaded to the container via a connector piece or via an intermediate piece and a connection nut. It is known to act upon the elastical sealing collar of the intermediate piece through the lever actuating the pump and the corresponding rods so that this collar is pressed away from the surface to be sealed at each actuation, leaving a passage for the ventilation of the container. It is also known to unblock a vent leading to the container connector via the pump piston sliding in a corresponding bore of the casing. In both cases it is necessary to control the ventilation in order to avoid unintended discharge of the liquid through the vent in the corresponding, or reversed position of the container with the spray pump threaded thereto. For this reason the vent has to be sealed towards the outside. The known actuation means for ventilation require additional parts, or bore channels.